# Find the Ratio of Father and Son

Parents age of father & son are in the ratio of 5 : 1 respectively. Seven years later this ratio becomes 3 : 1. What is the son’s present age in years ?

- 8
- 7
- 6
- 5

**Answer: (2) 7**

**Explanation:-**

Present age of the father and son in the ratio = 5:1

Then, let be the age of father is 5X and age of the son is X.

According to the question,

(5X + 7)/(X + 7 ) = 3/1

5X + 7 = 3X + 21 (by cross multiplication)

5X – 3X = 21 – 7

2X = 14

X = 14/2

X = 7

Hence, the age of the son is 7 years.